[Because what Overthinking It really needs is more Matts, we present this BTTF guest post from Matthew Silver. —Ed.]

Arguably, no movie involving time travel can ever actually make sense in the realm of continuity. I have to give tremendous credit to the Back To The Future writers for taking it on in the first place. This series has it all: paradox, parallel timelines, and altering history both past and future.

As an audience, we all cope with the discrepancies in different ways. Some of us rationalize the impossible because it’s the only way we can enjoy the reality presented to us. (Have you seen Heroes this season?) Some of us believe wholeheartedly in “suspension of disbelief” and are all too understanding of the limitations of Hollywood (Ross, Joey, and Chandler love the Die Hard films, yet they don’t hesitate to accept Bruce Willis when he shows up on Friends as a guest character). And then there are those of us who just unconditionally believe everything we see and hear. [Not on this site. —Ed.]

For those of us who will never be satisfied without a little digging, I present the following theories.